Creating a Dormer Using Slope Arrows

1. Sketch a roof footprint, including slope-defining lines.
2. While in sketch mode, click Modify | Create Roof Footprint tabModify panel (Split Element).
3. Split one of the lines in the footprint at 2 points, creating a middle line segment (the dormer segment), and then click Modify.
   
4. If the dormer segment is slope-defining (), select the line, and on the Properties palette, clear Defines Roof Slope.
5. Click Modify | Create Roof Footprint tabModify panel (Slope Arrow), and sketch a slope arrow from one end of the dormer segment to its midpoint.
   

   Correct placement of cursor for slope arrow

6. Click Slope Arrow again, and sketch a second slope arrow from the other end of the dormer segment to its midpoint.
   

   Properly sketched slope arrows

7. Click (Finish Edit Mode), and open a 3D view to see the results.
   

   Hip roof with dormer